This invention relates to actuator arms for data storage disc drives, and particularly to rigid actuator arms formed of pliable material, such as sheet metal, with integral struts arranged to support an actuator coil.
Rotating disc data storage devices store data along concentric tracks of a rotatable disc. An actuator assembly positions a transducer adjacent a selected track to transfer data between the disc media and the transducer. Electrical conductors couple the transducer to external circuitry, such as a data processor, so that data may be transferred to the transducer to write data to the medium and so that data read from the from the medium by the transducer may be transferred from the transducer. The actuator assembly consists of a rigid actuator arm that is pivotably mounted to the frame of the disc drive, a flexible suspension at the distal end of the actuator arm, a transducer mounted to the flexible suspension to xe2x80x9cflyxe2x80x9d a predetermined distance from the rotating storage medium, and a motor that rotates the actuator arm about the pivot point to move the transducer across the tracks on the medium. The suspension is resilient to provide a force, or load, to counter the upward force imposed on the transducer by the air movement supporting the transducer as it flies adjacent the rotating medium.
It is important that the actuator assembly have minimum weight to minimize inertia that may adversely affect the response of the motor and arm to actuation signals to move the transducer across tracks of the medium. The arm of the actuator assembly must be sufficiently rigid so that impulse and acceleration forces on the arm during a track seek operation does not bend or distort the arm.
Presently, arms of actuator assemblies are constructed of sturdy, lightweight materials, such as aluminum and aluminum alloys, plastic, and metal encapsulated plastic. The flexible suspension is attached to a distal end of the arm, such as by fasteners, swaging, staking, etc. Additionally, support mechanisms are employed to attach the motor, such as a coil, to the proximal end of the arm. These attachment mechanisms add weight to the actuator assemblies, adversely affecting inertia. Moreover, these attachments often require multiple assembly steps, adding to the cost of the actuator assembly. The present invention provides a solution to these and other problems, and offers other advantages over the prior art.
In accordance with the present invention, an actuator arm for a rotary actuator assembly is arranged to position a transducer adjacent a track on a rotatable data storage medium of a disc drive to transfer data between the transducer and the medium. The actuator arm comprises a substantially planar sheet of pliable material defining a longitudinal actuator arm having longitudinal edges, a distal end for supporting the transducer, a proximal end supporting an actuator coil, and a bore hole through the sheet having an axis aligned with the pivot bearing axis. The bore hole is arranged to receive the pivot bearing on the disc drive so that the arm may pivot about the pivot bearing axis for arcuate movement of the transducer. A strut integral with the sheet extends substantially normal to the plane of the sheet along at least a portion of at least one longitudinal edge and/or the proximal end of the arm. The strut provides rigidity to at least a portion of the arm.
In one embodiment, the strut includes a first integral strut portion extending along at least a portion of at least one longitudinal edge of the arm and a second integral strut portion defining a support at the proximal end of the arm. The actuator coil is wrapped about the support on the sheet.
In another embodiment, the strut includes first and second strut portions that extend along opposite longitudinal edges of the arm from a region of the bore hole to a location proximal the distal end. The strut portions define a rigid portion between the strut portions and a flexible suspension region distal to the rigid portion.
Other features and benefits that characterize embodiments of the present invention will be apparent upon reading the following detailed description and review of the associated drawings.